Sheet product dispensers, such as paper towel dispensers or tissue dispensers, provide on-demand sheet product to a user from a supply of sheet product stored within the dispenser, such as in roll form. The sheet product is dispensed from the roll by passing one end of the sheet product through a pair of rollers. Depending on the type of dispenser, dispensing may be accomplished automatically (e.g., with a motor) or manually (e.g., using the force a user applies). As the user pulls the sheet product, cutting arrangements (or perforations) may be used to separate a portion for use (e.g., a dispensed portion).
Some dispensers have a single roll of sheet product usable for dispensing. Others have multiple rolls, one or more being stored for use once the first roll is depleted. In either type of dispenser, it is desirable to avoid an empty condition where no sheet product is dispensed.